Hi,
you could use instance overriding with one of:
set_inst_override_by_type
set_inst_override_by_name Configures the factory to create an object of the override’s type whenever a request is made to create an object of the original type using a context that matches full_inst_path.
set_type_override_by_name Configures the factory to create an object of the override’s type whenever a request is made to create an object of the original type, provided no instance override applies.
See the UVM doc for more details.
In uvm-1.2/docs/html/index.html, Chapter “Factory”->“uvm_factory”
downloaded from UVM (Universal Verification Methodology)
Hope that was what you were looking for.